Hi, the following trick worked for me. Since I am using the Dutch version of Windows I must guess what the english terms are.
Go to your Windows configuration screen
Choose add new hardware
Do NOT choose automatic but choose ´Select hardware from list´
Under hardwaretype choose somthing USB
Then click on the ´Have disk´button and select the driver you have copied to C:\gp32drivers
Follow the onscreen intrsuctions.
Hope this helps.